The project is a study comparing stomach and colon cancer mortality between Puerto Rico and Puerto Ricans in New York City. Data tapes containing information on all deaths from cancer of the colon, rectum, and stomach occurring between January 1, 1975, and December 31, 1979, and data tapes of the same diseases from reviews of hospital records, will be provided. Biometry Branch will collaborate on all aspects of the study design, accuracy, and completeness of data provided.